end-autocomplete.sh

#!/bin/bash

if [ -z "$1" ] || [ -z "$2" ] 
then
 echo "Parameter 1 or 2 missing"
 kill -INT $$
fi

i=0
array=()
for file in .* *; do # proper way to do it : https://unix.stackexchange.com/a/162589
	filename=${file##*/}
	base=${filename%.*}
	ext=".${filename##*.}"
	l_ext=${#ext}
	l=${#2}
	search=""
	if [[ ${2:-l_ext} == $ext ]]; then # if user type the extension
		search=${filename: -l}
	else
		search=${base: -l}
	fi
	if [[ $search == $2 ]]; then
		array[$i]=$filename;
		i=$((i+1))
	fi
done

found=${#array[@]}
if [[ $found == "0" ]]; then
	echo "No corresponding file found"
elif [[ $found == "1" ]]; then
	$1 ${array[0]}
else
	echo "too many files found :"
	for a in ${array[*]}; do
		echo "* ${a}";
	done
fi

# ${variable#pattern}  Trim the shortest match from the beginning
# ${variable##pattern} Trim the longest match from the beginning
# ${variable%pattern}  Trim the shortest match from the end
# ${variable%%pattern} Trim the shortest match from the end

Let's try to build a script that allow autocomplete from the end of the word. For example, if you have a couple of files with the same beginning :

• 2018-1
• 2018-2
• 2018-3

You can just type ./end-autocomplete.sh vim 1, and the script will open 2018-1 in vim.